<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!--准备好一个“容器”-->
<div id="test"></div>

<!--引入react核心库-->
<script type="text/javascript" src="../js/react.development.js"></script>
<!--引入react-dom，用于支持react操作DOM -->
<script type="text/javascript" src="../js/react-dom.development.js"></script>
<!--引入babel，用于将jsx转为js -->
<script type="text/javascript" src="../js/babel.min.js"></script>

<script type="text/javascript" src="../js/prop-types.js"></script>

<script type="text/babel">
    //创建组件
    class Life extends React.Component {
        state = {opacity: 1}

        death = () => {
            clearInterval(this.timer)
            ReactDOM.unmountComponentAtNode(document.getElementById('test'))
        }

        //组件挂载完毕
        componentDidMount() {
            console.log('组件挂载完毕')
            this.timer = setInterval(() => {
                let {opacity} = this.state
                opacity -= 0.1
                if (opacity <= 0) opacity = 1
                this.setState({opacity})
            }, 200)
        }

        //组件将要卸载
        componentWillUnmount() {
            console.log('组件将要卸载')
            clearInterval(this.timer)
        }

        //初始化渲染、状态更新之后
        render() {
            console.log('render')
            return (
                <div>
                    <h2 style={{opacity: this.state.opacity}}>React学不会怎么办？</h2>
                    <button onClick={this.death}>不活了</button>
                </div>
            )
        }
    }

    //2.渲染组件到页面
    ReactDOM.render(<Life></Life>, document.getElementById('test'))
</script>
</body>
</html>

